*{
    box-sizing: border-box;
}


#board1{
   
    border: solid 1px black;
    border-collapse: collapse;
    width: 720px;
    background-image: url(1.jpg);
}
#board1 td{
    border: solid 1px black;
}
td{
    width: 40px;
    height: 40px;
    text-align: center;
    vertical-align: center;
}
#outline{
    margin-top: 45px;
    border: solid 4px black;
    padding: 10px;
    display: inline-block;
}
body{
    text-align: center;
    margin: 0;
}
#board2{
    margin-top: 40px;
    /*border: solid 1px red;*/
    border-collapse: collapse;
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 760px;
    /*保证td不被撑变形*/
    table-layout: fixed;
}
#board2 td{
    /*border: solid 1px red;*/
}
[chess=black]:before{
    display: inline-block;
    width: 25px;
    height: 25px;
    background-color: black;
    content: "";
    border-radius: 50%;
}
[chess=white]:before{
    display: inline-block;
    width: 25px;
    height: 25px;
    background-color: white;
    content: "";
    border-radius: 50%;
    border: solid 1px black;
}
#control{
    position: absolute;
    width: 100%;
    padding: 0 200px;
    top: 10px;
}
.left{
    float: left;
}
.right{
    float: right;
}
button{
    border: none;
    background-color: mediumseagreen;
    border-radius: 5px;
    height: 30px;
    color: brown;
    cursor: pointer;
}


